An aquous solution of a substance give a white precipitate on tretement with dilute hydrochloric acid, which dissolve on heating. When hydrogen sulphide is passed through the hot acidic solution, a black precipitate is observed.the substance is a

Options

A. `Hg_(2)^(2+)` salt
B. `Cu^(2+)` salt
C. `Ag^(+) ` salt
D. `Pb^(2+)` salt

Explanation

`PbCl_(2)` is soluble only in hot water. `Pb^(2+)` ions give black ppt. of PbS with `H_(2)S`.